Ammonia (NH3) and other nitrogen containing compounds (often with odorous and unpleasant smell) are contaminants in the air, harmful to human health. Methods have been developed to eliminate such contaminants.
Supported metal oxide catalysts are found to be effective in selective catalytic oxidation of NH3 and nitrogen containing compounds. (see L. Gang, J. van Grondelle, B. G. Anderson and R. A. van Santen, J. Catal. 186: 100-109 (1999); L. Gang, B. G. Anderson, J. van Grondelle, R. A. van Santen, W. J. H. van Gennip, J. W. Niemantsverdriet, P. J. Kooyman, A. Knoester and H. H. Brongersma, J. Catal. 206: 60 (2002); Lu Gang, B. G. Anderson, J. van Grondelle and R. A. van Santen, Appl. Catal. B 40: 101 (2003)).
In the prior art, supported metal oxide catalysts usually comprise of nano-sized metal oxide particles in the crystalline form adhered to another metal oxide support. One disadvantage of such supported metal oxide catalyst is the low catalytic activity at low temperature. Thus, a high temperature (>250° C.) is required for efficient degradation. Another disadvantage is the high metal oxide loading and formation of by-products (e.g. nitrogen oxides (NOx) and nitrous oxides N2O) because of the selectivity problem of these catalysts. A new process is needed to prepare novel support material for supporting meal oxide catalyst so that the catalyst exists on the support material in the form of monomer or polymer but not in the crystalline form to enhance the catalyst's activity and selectivity.